(Bloomberg) -- Pfizer Inc. shares tumbled in early trading after its disappointing forecast for next year showed the purchase of a leading cancer drugmaker isn’t enough to fill the ever-growing hole from its flailing Covid franchise.

Pfizer’s falling Covid product revenue continued to plague the pharma giant, as projected sales of its shot and pill missed analysts’ estimates by wide margin. The shares fell 6.4% in trading before US markets opened. Rival Covid shot maker Moderna Inc. lost 4.5% and American depositary receipts of Pfizer’s vaccine partner BioNTech SE slipped 3.7%.

Pfizer is aiming to boost its business with its $43 billion takeover of Seagen Inc., set to close Thursday after the deadline for the Federal Trade Commission to oppose the deal expired this week. But demand continues to wither for its Covid vaccines and pills, which Pfizer now sees bringing in close to $6 billion less than the $13.8 billion expected by Wall Street next year.

Seagen is a leader in developing therapies that deliver cancer-fighting medicine directly at the tumor site with minimal damage to surrounding tissues. These have become among the most desired oncology products, with AbbVie Inc., Bristol Myers Squibb Co. and Merck & Co. recently clinching billion-dollar deals to gain access to them.

The big miss on profit likely isn’t due to waning Covid sales alone, and is sure to be the focus of questions on Wednesday morning’s conference call with analysts, according to Bloomberg Intelligence analyst John Murphy.

Overall sales for 2024 will reach $58.5 billion to $61.5 billion, Pfizer said Wednesday in a statement, a range lower than the $62.9 billion average projected by Wall Street. It sees adjusted annual earnings of $2.05 to $2.25 a share, well below the average estimate of $3.21. 

The company also said it will raise its cost-cutting goals to at least $4 billion from a previous pledge of $3.5 billion it made earlier this year.

This story was produced with the assistance of Bloomberg Automation.

(updates with analyst comment in fifth paragraph.)

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